Police arrested the 22-year-old unemployed suspect on suspicion of attempted murder, the report said.
A knife-wielding man stabbed and killed one person and injured two others on a Japanese bullet train, police said on Sunday.
What appear to be fleeing passengers' belongings are strewn on the floor of a shinkansen vehicle next to the one where a knife-yielding man killed a male passenger and injured two women on June 9, 2018.
The 22-year-old suspect told investigators that he was irritated and picked the targets at random.
The attack occurred at about 9:50 pm, soon after the Tokaido Shinkansen line train left Tokyo Station.
Two women were also injured.
The attack occurred on Saturday night, when the train operated by Central Japan Railway was traveling west in Kanagawa Prefecture, south of Tokyo.
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Police are investigating the motive of the attack.
Umeda's family issued a statement through a lawyer, saying, "We do not have words to express the sorrow of suddenly losing a loved one". At least two knives were found at the scene of the crime. The train was crowded with women thought to have attended an event.
Witnesses said passengers fled in panic, some of them in tears.
After he started living with his grandmother, she said he mainly stayed home, reading books and surfing the internet.
"I have been always anxious about him", his grandmother said in a telephone interview early Sunday. (JR Tokai) announced it would move up its plan to install more security cameras in bullet trains.
Stabbing attack in Japan's bullet train leaves 1 killed, 2 injured, Sputnik reported.